With premiere week looming (and a few freshmen getting a head start this week), anticipation is building over which new shows will hit and which is this season’s, gulp, Lone Star. Though network brass are often heard saying they “love all their children equally” this time of year, they know which are their big bets (hint: just check out which shows get all the promos to know which are each network’s darlings).

But despite endless testing and projections by some of the smartest people in the business (often found in the research departments at networks), there are still many things network executives are waiting to see unfold just like the rest of us.

So, from an informal polling of broadcast network bigwigs, here are four things they will be tuning in to find out when the new season kicks off.

How Big Will ‘The X-Factor’ Be?

Fox’s aptly named The X Factor is just that for the story line that will shape the fall season and beyond, if the Fox reality show lives up to its hype. The Simon Cowell-led vocal competition series was top-of-mind with every network exec we asked about what they are most waiting to see shake out from this fall season.

With the reunion of Cowell and Paula Abdul, the preseason casting drama and the franchise’s proven hit status in the U.K., no one doubts that the series will open big—the question is just how big. “If it does Idol-type numbers, that will be a bit of a gamechanger,” says one rival executive. “That gives [Fox] strength pretty much throughout the season.”

Then there is the question of if Fox appears to have another American Idol on its hands, how that will affect Idol when it returns, and really the entire singing competition show genre. After a reinvented 10th season, Fox execs are feeling confident about Idol’s future, but a flashy new version (with Cowell) could take some of the shine off. And while the breakout success of The Voice seemed to quell fears (for now) that the genre had reached its saturation point with viewers, The Sing-Off joining the crowd this fall, in addition to The X Factor, will put that theory to the test once again.

Are There Enough Laughs To Go Around?

Perhaps recognizing where the strength of network television is (and isn’t), the Big Four are all putting a push behind comedy this fall, and The CW is now saying it will get back in that business as well. “I think there’s a real effort on all of the networks to add more comedy to their schedule,” says one network executive.

And there is an effort to do so in different ways. While CBS never got out of the multi-camera game, the format had fallen out of fashion at the other networks in recent years. This fall, Fox will have a multi-camera comedy in I Hate My Teenage Daughter; ABC has one in Tim Allen’s Last Man Standing; and NBC will launch Whitney.

But establishing new comedy may prove difficult, especially for ABC and NBC, which will both attempt to open up a second night of the genre. ABC faces a potentially easier go of it with the name recognition of Allen, while NBC will try to get its Wednesday laffers out ahead of the X Factor crush. Whitney, a top marketing priority of NBC, faces the task of following its Thursday lineup of single-camera, droll comedies.

And the stakes for success are high. Comedies repeat well and bring in lucrative syndication dollars to the studios, plus they have tended to be where broadcast has nabbed most of its Emmys in recent years. “Every year, the pressure is on because if you let your comedy stock dwindle down, it gets really tough to build it back up again,” says the network exec.

Who Will Start the Week Off Right?

If The X Factor is fall’s biggest launch, broadcast execs seem to be in consensus that Terra Nova is No. 2. A pilot episode with a pricetag reportedly above $10 million, plus multiple production (and hence premiere date) delays, makes the anticipation for the Steven Spielberg-produced project high. Fox’s event-like launch for the series means potentially big ratings for the premiere; the question is whether the series will teeter off into a niche sci-fi show or can cross over to a bigger audience, as Lost did.

Monday also sees the return of Two and a Half Men with its new star, Ashton Kutcher. While the premiere will no doubt get a high curiosity tune-in (if only to see how Chuck Lorre and team chose to kill off Charlie Sheen’s character), execs will be looking to see if Kutcher can get the show out of its ! rst weeks and back to its top-rated perch.

On the reality side, The Sing-Off, successful as a holiday-season strip, will be tested in its new expanded format. In September it will face much stiffer competition, particularly scheduled against ABC reality juggernaut Dancing Withthe Stars, whose season 13 cast includes potential ratings bait in Chaz Bono and, yes, Nancy Grace.

Will Retro Be Back in Fashion?

The interest in the fall’s period dramas, ABC’s Pan Am and NBC’s The Playboy Club, is mostly to see if a genre that AMC turned into a (cable) success can find a wider audience in broadcast. “I’m very curious to see the audience appetite for that type of a show, if these ’60s kinds of shows can get a broad audience,” says another network executive.

While Mad Men’s roughly 2 million viewers an episode would cancel a show within weeks on broadcast, the series is critically acclaimed and has cultural recognition wider than its audience (Banana Republic recently launched a clothing line inspired by it). And with other period projects in development—NBC recently picked up a western and a 1980s wrestling drama—the performance of Pan Am and The Playboy Club could determine whether more new TV will look old again down the line.E-mail comments to amorabito@nbmedia.com and follow her on Twitter: @andreamorabito